Tablet devices, such as smart phones, mobile phones, the Personal Handy-phone System (PHS), and personal digital assistants (PDA), are becoming widely used. Because tablet devices are compact and lightweight, a user can use a tablet device anywhere.
When a user operates a tablet device, the user touches, with his/her finger, an item from among various items displayed on the tablet device's touch panel. For example, the user performs a touch operation to select a hypertext on a Web page displayed on the touch panel, to enlarge an image, to replay or stop a video image, and the like. These related-art examples are described, for example in Non-Patent Document 1: “MobiGaze, Development of a Gaze Interface for Handheld Mobile Devices”, Apr. 12-13, 2010.
However, with the conventional technology, there is a problem in that, it is not convenient to operate the touch panel with one hand.
For example, when a user is holding a hand strap in a train or carrying a bag or an umbrella in one hand, the user needs to operate the touch panel of the tablet device with his/her other hand. When a user operates a touch panel with just one hand, the reach of the user's fingers is limited and thus the touch panel is inconvenient for the user to operate.